The Department of Agriculture has decided it will not tamper with the definition of the word "meat" by allowing it to include a mixture of crushed bone, pure fat and bits of flesh.

Instead, in proposed regulations unveiled last week, USDA would rename the mixture, which has been called Mechanically Deboned Meat, "tissue from ground bone."

According to Assistant Agriculture Secretary Carol Foreman, "We are not prepared to redefine meat to include connective tissue and some ground bone. Instead we will define it (MDM) as a meat food product."

Foreman said any processed meat products that contained this tissue would have to list its presence on the principal display panel of the label beside the name of the product. For example: Beef stew made with "tissue from ground bone."

In April 1976, USDA approved the use of MDM in processed meat products without an opportunity for public comment and without discussion of the health and safety aspects of the pulverized bone. A coalition of consumer groups took the Agriculture Department to court, charging the agency with illegal actions. The court ruled in favor of the coalition and the use of MDM was suspended.

Mechanical deboning recovers 10 to 15 per cent more meat from carcass than is possible by hand deboning methods.

USDA asked an advisory panel to settle the health and safety issues of MDM. The proposed regulations are based on the panel's findings. These include some limitations on the use of MDM or ground bone tissue. Bebones, the substance would not be permitted infant and toddler food. Fluoride might cause mottling of young children's teeth.

The maximum fat content of the ground bone tissue would be set at 30 per cent, the minimum protein content at 14 per cent. The quality of the protein would be set below that of lean beef. Protein quality is determined by its ability to maintain the body's growth. Technically this is known as Protein Efficiency Ratio (PER). Lean beef has a PER of 2.85. The PER of the ground bone tissue would be 2.50. It could not be used for more than 20 per cent of the meat component in any processed meat product.

The public can comment on the proposal until Dec. 5.